Now multi-functional sofas have seen wide application. Generally, these available sofas provide three basic positions, a standard non-reclining retracted position, an extended position and a reclining position. In the retracted position, a seat is substantially horizontally oriented while a backrest is substantially vertically arranged. In addition, if the sofa comprises a footrest linkage, the linkage is folded to prevent the footrest from extending. In an extended position, usually a position suitable for watching TV, the footrest is extended forward of the seat while the backrest is maintained vertical enough to permit an occupant of the seating unit to watch TV comfortably. In the reclining position, the backrest is orientated backward (reclined) from the extended position to form an obtuse angle relative to the seat for rest or sleeping.
However, in the retracted position, the mechanical extending linkage of these known sofas takes up a larger space even if being folded, which consequently results in a thick position for placing legs as well as an ugly appearance and unpopular form. Therefore, it is necessary to have a space-saving and simple design.
Besides, in the extended position and the reclining position, the total extended length of currently available footrest linkage for sofas is still not long enough to meet the requirement in comfort. Therefore, there is a need to provide a design with increased extended length.